Student's t Approximations for Three Simple Robust Estimators

1988 ◽  
Vol 83 (404) ◽  
pp. 1203 ◽  
Author(s):  
Kartik R. Patel ◽  
Govind S. Mudholkar ◽  
J. L. Indrasiri Fernando
Keyword(s):  
Robust Estimators ◽  
Student’S T

RISKS OF ANEMIA DEVELOPMENT IN DONORS ACCORDING TO INHERITED PREDISPOSITION AND REGULARITY OF BLOOD DONATION

2020 ◽  
pp. 72-83
Author(s):  
I.M. Vorotnikov ◽  
V.A. Razin ◽  
I.M. Lamzin ◽  
M.N. Sokolova ◽  
M.E. Khapman ◽  
...  
Keyword(s):  
Blood Donors ◽  
Blood Donation ◽  
Hla Antigens ◽  
Hla Typing ◽  
Main Role ◽  
Inherited Predisposition ◽  
Group 2 ◽  
Student’S T ◽  
A Prospective Study ◽  
Group 1

Anemia is one of the most common complications of blood donation. Thus, the objective of the paper was to assess the risks of anemia development in donors according to the regularity of donation and inherited predisposition. Materials and Methods. The authors carried out a prospective study, which included 241 blood donors, using random sampling and case-control techniques. Depending on blood donation frequency, the donors were divided into 2 groups: Group 1 consisted of 122 people (51.5 %) frequently donating blood; Group 2 included 119 people (48. 5 %) rarely donating blood. We studied the initial indicators of a general blood test and the same indicators a year after the first blood donation. Additionally, we performed HLA typing of donors. Statistica v. 8.0 software package (Stat Soft Inc., USA) was used for statistical analysis. To compare two independent samples, we used a nonparametric Mann-Whitney U-test and a parametric Student’s t-test (depending on the type of distribution). To assess anemia risks, the odds ratio was calculated. Results. One year after the first blood donation, anemia was diagnosed in 13 people (10.6 %) in Group 1 and in 7 people (5.9 %) in Group 2 (p=0.179). A11 and B7 HLA antigens did not increase anemia risks in group 1 (OS=1.257 (95 % CI 0.318–4.973) and OS=0.240 (95 % CI 0.051–1.134, respectively). HLA-antigens A11 and B7 did not increase anemia risks in Group 1 (OR=1.257 (95 % CI 0.318-4.973) and OR=0.240 (95 % CI 0.051–1.134), respectively). In group 2, antigen-A11 was also an insignificant factor (OS=2.902 (95 % CI 0.606-13.889)) for anemia development. Whereas, antigen-B7 increased anemia risks by 14 times (OS=14.364 (95 % CI 1.644-124.011)). Conclusion. In rare blood donors, it is the genetic factor that plays the main role in anemia development. High prevalence rates of anemia in frequent blood donors are probably determined by other factors. Keywords: anemia, blood donors, HLA typing. Механизмы развития анемий и факторы, их индуцирующие, остаются до конца не изученными. Целью исследования стало изучение риска развития анемии у доноров крови в зависимости от частоты донации и наличия наследственной предрасположенности к развитию анемии. Материалы и методы. Проведено проспективное исследование, выполненное методами случайной выборки и «случай-контроль», в которое вошел 241 донор крови. В зависимости от частоты сдачи доноры были поделены на 2 группы: группу 1 составили 122 чел. (51,5 %), часто сдающие кровь; группу 2 – 119 чел. (48,5 %), редко сдающих кровь. Изучались исходные показатели общего анализа крови и через год от начала донации. Дополнительно проводилось HLA-типирование доноров. Статистический анализ осуществлялся с применением программы Statistica v. 8.0 (Stat Soft Inc., США). Для сравнения двух независимых выборок использовался непараметрический U-критерий Манна–Уитни и параметрический t-критерий Стьюдента (в зависимости от типа распределения). Для оценки риска возникновения анемии рассчитывалось отношение шансов. Результаты. Через год с момента первой сдачи крови в группе 1 выявлено 13 чел. (10,6 %) с анемией, в группе 2 – 7 чел. (5,9 %) (р=0,179). Наличие HLA-антигенов А11 и B7 не повышало риск развития анемии в группе 1 (ОШ=1,257 (95 % ДИ 0,318–4,973) и ОШ=0,240 (95 % ДИ 0,051–1,134 соответственно). В группе 2 наличие гена А11 также являлось незначимым фактором (ОШ=2,902 (95 % ДИ 0,606–13,889), присутствие гена В7 в 14 раз повышало риск развития анемии (ОШ=14,364 (95 % ДИ 1,664–124,011). Выводы. Высокий риск развития анемии у редко сдающих кровь доноров обусловливается генетическими факторами. Высокая распространённость анемии у часто сдающих кровь доноров, вероятно, определяется другими факторами. Ключевые слова: анемия, доноры крови, HLA-типирование.

STUDYING SOME CLINICAL AND PARACLINICAL CHARACTERISTICS OF POSMATURE BABIES CARED IN NICU AT HUE UNIVERSITY HOSPITAL

2012 ◽  
pp. 74-84
Author(s):  
Thi Kieu Nhi Nguyen
Keyword(s):  
Respiratory Rate ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
University Hospital ◽  
Maternal Characteristics ◽  
Exact Test ◽  
Menstrual Cycles ◽  
Term Newborns ◽  
Student’S T ◽  
The Individual

Objectives: 1. Estimating the ratios of clinical and paraclinical signs of post-term newborns hospitalized at Pediatric Department of Hue University Hospital. 2. Identifying the relation between clinical signs and paraclinical signs. Materials and Method: 72 post- term babies < 7 days of life hospitalized at NICU from 2010/5 to 2011/4. Classification of post - term newborn was based on WHO 2003: gestational age ≥ 42 weeks with clinical manifestations: desquamation on press with fingers or natural desquamation, withered or meconial umbilicus, meconial long finger nails (*) or geatational age still < 42 weeks with theses clinical manifestations (*). Data were recorded on a clinical record form. Per-protocol analysis of clinical outcomes was performed by using Medcalc 11.5 and Excell 2007. Analyses used the χ2 test or Fisher's exact test for categorical data; Student's t test was used for continuous data and the Mann-Whitney U test for nonparametric data. Data were presented as means or proportions with 95% CIs. Results: Clinical characteristics: Tachypnea and grasp were main reasons of hospitalisation (48.61%). Poor feeding, vomitting (16.67%). Asphyxia (8.34%). Jawndice (6.94%). Hypothermia < 36.50C (13.89%), fever (13.89%). Tachypnea (59.72%). Bradycardia (1.39%). Poor feeding (11.11%). Hypertonia (9.72%). Paraclinical characteristics: Erythrocytes < 4.5.1012/l (51.39%), Leucocytes 5 – 25.103/mm3 (81.94%), Thrombocytes 100- 400.103/mm3 (94.44%). Hemoglobinemia < 10mg/l (67.61%). Maternal characteristics: Menstrual cycles regular (75%). Primiparity (75%). Amniotic volume average (70.42%), little (29.58%). Aminiotic liquid clair (62.5%), aminiotic liquid yellow (4.17%), aminiotic meconial liquid (33.33%). Maternal manifestation of one of many risk factors consist of genital infection; urinary infection; fever before, during, after 3 days of birth; prolonged delivery; medical diseases influence the foetus (75%). The relation between clinical signs and paraclinical signs: There was significantly statistical difference: between gestationnal age based on obstetrical criteria and amniotic volume on ultrasound (p < 0.05); between birth weight and glucosemia p < 0.02). There was conversional correlation of average level between erythroctes number and respiratory rate (r = - 0.5158; p < 0,0001), concordance correlation of weak level betwwen leucocytes number and respiratory rate r = 0.3045; p = 0.0093). Conclusion: It should made diagnosis of postterm baby based on degree of desquamation. The mother who has menstrual cycles regular is still delivered of a postterm baby. A postterm baby has the individual clinical and paraclinical signs.

Scientific Substantiation of the Innovative Model of Catering for Cadet Corps Students

2020 ◽  
pp. 31-35
Author(s):  
Novikova ◽  
SP Romanenko ◽  
MA Lobkis
Keyword(s):  
Correlation Coefficient ◽  
School Environment ◽  
Developmental Disorders ◽  
Pearson Correlation ◽  
Statistical Significance ◽  
Regression Analyses ◽  
Healthy Nutrition ◽  
Innovative Model ◽  
Scientific Substantiation ◽  
Student’S T

Introduction: In the Russian Federation, much attention is traditionally paid to military education and training. A special place in its structure is occupied by the system of cadet classes and corps. A distinctive feature of the learning mode in such institutions is a combined effect of standard and specific factors of indoor school environment and intensive physical activity owing to sports, applied military and drill training. No evidence-based methods of establishing nutrient requirements of children in modern conditions of cadet corps have been developed so far, which predetermines the potential of transforming nutrition from a health-saving factor into a health risk factor. Our objective was to provide a scientific substantiation of the model of healthy nutrition for students of cadet-type educational establishments. Methods: The statistical significance of the correlation was evaluated using the Student’s t-test. Correlation and regression analyses were used to assess cause-and-effect relationships. The Pearson correlation coefficient (rxy) was used as an indicator of the strength of the relationship between quantitative indicators x and y, both having a normal distribution. Correlation coefficient (rxy) values were interpreted in accordance with the Chaddock scale. For the purpose of statistical modeling, the method of multiple linear regressions was used. Conclusions: We substantiated the innovative model of organizing healthy nutrition for students of cadet-type schools based on the correlation and regression analyses with determination of statistical significance of the studied characteristics. Its efficiency indicators include an increase in average functional capabilities of students by more than 10 % and a reduction in the probability of developmental disorders by more than 25 %.

PREEMPTIVE ANALGESIA WITH AMITRIPTYLINE IN WOMEN UNDERGOING ABDOMINAL HYSTERECTOMY: A RANDOMIZED CLINICAL TRIAL

2020 ◽  
pp. 2-5
Author(s):  
Antônio Henriques De França Neto ◽  
Alexandre Magno Nóbrega Marinho ◽  
Eveline Pereira De Arruda Agra ◽  
Priscilla Guimarães Alves ◽  
Josikwylkson Costa Brito ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Postoperative Pain ◽  
Pressure Pain Threshold ◽  
Abdominal Hysterectomy ◽  
Tricyclic Antidepressant ◽  
Preemptive Analgesia ◽  
Chi Square ◽  
Double Blind ◽  
Exact Test ◽  
Student’S T

The concept of preemptive analgesia, albeit long-standing, has reemerged. Consequently, recent research has focused on testing a variety of drugs preoperatively to prevent the occurrence of postoperative pain, a major factor of morbidity. Amitriptyline is a tricyclic antidepressant used to treat chronic pain. Because amitriptyline acts on pain transmission pathways, it could theoretically be used as an agent for the prevention of postoperative pain. This study evaluated the effectiveness of amitriptyline in preventing pain in patients submitted to hysterectomy, the most commonly performed gynecological surgery. A randomized, double-blind clinical trial was conducted with 145 patients, 72 of these receiving amitriptyline and 73 placebo. All patients were evaluated at 6, 12, 24 and 48 hours after surgery using a visual analog scale (VAS) for pain and algometry to determine the pressure-pain threshold. Statistical analysis was conducted using the chi-square test of association, Student's t-test, and the Mann-Whitney test, with Fisher's exact test being used whenever appropriate. No statistically signicant difference was found between the two groups with respect to pain at any of the time points evaluated, leading to the conclusion that at a dose of 25 mg, amitriptyline is ineffective in preventing postoperative pain in patients submitted to abdominal hysterectomy

Microneedle-Assisted Percutaneous Transport of Magnesium Sulfate

2020 ◽  
Vol 17 (2) ◽  
pp. 140-147
Author(s):  
Karna B. Ghimirey ◽  
Kevin Ita
Keyword(s):  
Confocal Microscopy ◽  
Stratum Corneum ◽  
Magnesium Sulfate ◽  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Magnesium Concentration ◽  
Porcine Skin ◽  
Time Curve ◽  
Student’S T

Objective: In vitro diffusion experiments were performed to assess the permeation of magnesium sulfate across pig skin. Method: The mean thickness of the dermatomed porcine skin was 648 ± 12 µm. Magnesium concentration was measured using inductively coupled plasma-optical emission spectroscopy. Transdermal flux of magnesium sulfate across MN-treated and untreated porcine skin was obtained from the slope of the steady-state linear portion of cumulative amount versus time curve. Results: Statistical analysis of the results was done with Student’s t-test. The transdermal flux of magnesium sulfate across microneedle-treated porcine skin was 134.19 ± 2.4 µg/cm2/h and transdermal flux across untreated porcine skin was 4.64 ± 0.05 µg/cm2/h. Confocal microscopy was used to visualize the microchannels created by a solid microneedle roller (500 µm). Conclusion: From our confocal microscopy studies, it was evident that the 500 μm long microneedles disrupted the stratum corneum and created microchannels measuring 191 ± 37 µm. The increase in transdermal flux across the microneedle-treated skin was statistically significant compared to that of controls, i.e., without the application of microneedles. With the application of microneedles, the transdermal flux of magnesium permeated over 12 h was approximately 33-fold higher in comparison to passive diffusion across an intact stratum corneum.

Serosal and cutaneous recordings of gastric myoelectrical activity in patients with gastroparesis

1994 ◽  
Vol 266 (1) ◽  
pp. G90-G98 ◽  
Author(s):  
J. D. Chen ◽  
B. D. Schirmer ◽  
R. W. McCallum
Keyword(s):  
Electrical Stimulation ◽  
Slow Wave ◽  
Test Meal ◽  
Frequency Change ◽  
Fasting State ◽  
Gastric Myoelectrical Activity ◽  
Myoelectrical Activity ◽  
Gastric Slow Wave ◽  
Student’S T ◽  
Student’S T Test

The aims of this study were to 1) investigate gastric myoelectrical activity in patients with gastroparesis, 2) validate the cutaneous electrogastrogram (EGG) in tracking the frequency change of the gastric slow wave, and 3) investigate the effect of electrical stimulation on gastric myoelectrical activity. Gastric myoelectrical activity was recorded in 12 patients with documented gastroparesis using serosal electrodes for > 200 min in each subject. All recordings were made at least 4 days after surgery. Each session consisted of a 30-min recording in the fasting state and a 30-min recording after a test meal. The test meal (liquid or mixed) was selected according to patient's tolerance. Electrical stimulation was performed in three subjects via the serosal electrodes at a frequency of 3 cycles/min. Gastric myoelectrical activity was recorded using serosal electrodes in each session. The serosal recording showed slow waves of 2.5 to 4.0 cycles/min in all 12 subjects. Absence of spikes was noted in 11 of the 12 subjects. The simultaneous serosal and cutaneous recording of gastric myoelectrical activity showed that the frequency of the EGG was exactly the same as that of the serosal recording. Liquid meals resulted in a significant decrease in slow-wave frequency (Student's t test, P = 0.006), and the EGG accurately reflected this change. Electrical stimulation had no effect on the frequency of the gastric slow wave and did not induce spikes.(ABSTRACT TRUNCATED AT 250 WORDS)

The Effect of Changes in Dialysate Volume on Glucose and Urea Equilibration

1994 ◽  
Vol 14 (3) ◽  
pp. 236-239 ◽  
Author(s):  
Edward C. Kohaut ◽  
F. Bryson Waldo ◽  
Mark R. Benfield
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Prospective Study ◽  
Body Surface ◽  
Patient Population ◽  
Different Ages ◽  
Student’S T ◽  
A Prospective Study ◽  
Dialysate Volume ◽  
Student’S T Test

Objectives To determine the effect of changing dialysate volume on urea and glucoseequilibration curves and to determine, if dialysate volume is prescribed on the basis of body surface area, whether equilibration curves will be consistent in patients of different sizes and ages. Design A prospective study wherein children with acute or chronic renal failure had peritoneal equilibration studies done with dwell volumes of 30 mL/kg, 40 mL/kg, and 1200 mL/m2. Patient Population Twenty-two children: 7 under 3 years of age; 8 between 3 and 10 years of age; 7 older than 10 years of age. Statistics Student's t-test. Results Urea and glucose equilibrated rapidly at dwell volumes of 30 mL/kg, slower at dwell volumes of 40 mL/kg, and slowest at dwell volumes of 1200 mL/m2. Equilibration curves were similar in children of different ages when dialysate volumes of 1200 mL/m2 were infused. Conclusion Dialysate volumes of 1200 mL/m2 should be used when equilibration studies are being done to compare individuals of different ages and sizes.

scholarly journals Data on Orientation to Happiness in Higher Education Institutions from Mexico and El Salvador

Data ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 27
Author(s):  
Domingo Villavicencio-Aguilar ◽  
Edgardo René Chacón-Andrade ◽  
Maria Fernanda Durón-Ramos
Keyword(s):  
Higher Education ◽  
El Salvador ◽  
Latin American ◽  
Higher Education Institutions ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Stepwise Multiple Regression ◽  
Teacher Student ◽  
And Gender ◽  
Student’S T

Happiness-oriented people are vital in every society; this is a construct formed by three different types of happiness: pleasure, meaning, and engagement, and it is considered as an indicator of mental health. This study aims to provide data on the levels of orientation to happiness in higher-education teachers and students. The present paper contains data about the perception of this positive aspect in two Latin American countries, Mexico and El Salvador. Structure instruments to measure the orientation to happiness were administrated to 397 teachers and 260 students. This data descriptor presents descriptive statistics (mean, standard deviation), internal consistency (Cronbach’s alpha), and differences (Student’s t-test) presented by country, population (teacher/student), and gender of their orientation to happiness and its three dimensions: meaning, pleasure, and engagement. Stepwise-multiple-regression-analysis results are also presented. Results indicated that participants from both countries reported medium–high levels of meaning and engagement happiness; teachers reported higher levels than those of students in these two dimensions. Happiness resulting from pleasure activities was the least reported in general. Males and females presented very similar levels of orientation to happiness. Only the population (teacher/student) showed a predictive relationship with orientation to happiness; however, the model explained a small portion of variance in this variable, which indicated that other factors are more critical when promoting orientation to happiness in higher-education institutions.

scholarly journals The Association between Difficulties with Speech Fluency and Language Skills in a National Age Cohort of Children with Down Syndrome

2021 ◽  
Vol 11 (6) ◽  
pp. 704
Author(s):  
Kari-Anne B. Næss ◽  
Egil Nygaard ◽  
Hilde Hofslundsengen ◽  
J. Scott Yaruss
Keyword(s):  
Down Syndrome ◽  
Language Skills ◽  
Typically Developing ◽  
Typically Developing Children ◽  
Cross Sectional ◽  
Exact Test ◽  
Children With Down Syndrome ◽  
Speech Fluency ◽  
Age Cohort ◽  
Student’S T

The present study (a) addressed difficulties in speech fluency in children with Down syndrome and typically developing children at a similar non-verbal level and (b) examined the association between difficulties with speech fluency and language skills in children with Down syndrome. Data from a cross-sectional parent survey that included questions about children’s difficulties with speech fluency, as well as clinical tests from a national age cohort of 43 six-year-olds with Down syndrome and 57 young typically developing children, were collected. Fisher’s exact test, Student’s t-test, linear regression, and density ellipse scatter plots were used for analysis. There was a significantly higher occurrence of parent-reported difficulties with speech fluency in the children with Down syndrome. Higher language scores were significantly associated with a lower degree of difficulties; this association was strongest for vocabulary and phonological skills. Although difficulties with speech fluency were not reported for all children with Down syndrome, a substantially higher occurrence of such difficulties was reported compared to that for typically developing children. The significant association between difficulties with speech fluency and the level of language functioning suggests that speech fluency and language skills should be taken into consideration when planning treatment for children with Down syndrome.

scholarly journals Acute Effects of Different Postactivation Potentiation Protocols on Traditional Rowing Performance

2020 ◽  
Vol 18 (1) ◽  
pp. 80
Author(s):  
Alfonso Penichet-Tomas ◽  
Jose M. Jimenez-Olmedo ◽  
Luis Serra Torregrosa ◽  
Basilio Pueo
Keyword(s):  
Effect Size ◽  
Muscle Power ◽  
Average Power ◽  
Postactivation Potentiation ◽  
Warm Up ◽  
Maximal Load ◽  
Rowing Performance ◽  
Load Intensity ◽  
And Performance ◽  
Student’S T

Postactivation potentiation (PAP) describes an initial muscular activation with a submaximal or maximal load intensity that produces acute improvements in muscle power and performance in subsequent explosive activities. The objective of this study was to compare the effect of different PAP protocols in rowing performance. A crossover design involving seven rowers was used, in which two different PAP protocols were applied: PAP of maximal conditioning contractions (PAP MCC) on a rowing ergometer to provide greater transferability and, thus, enhance the magnitude of PAP stimuli on subsequent rowing performance; and PAP of maximal strength contractions (PAP MSC) in half squat and bench pull exercises, similar to the main exercises in rowing strength training, to perform a 20 s “all-out” test simulating a competition start. Student’s t-test was used to compare means of the variables (p < 0.05). Effect size statistics were calculated using Cohen’s d. The PAP MCC protocol resulted in significant differences, with an extremely large effect size in average power output (p = 0.034, d = 0.98) in the first 3 (p = 0.019, d = 1.15) and first 5 (p = 0.036, d = 0.91) strokes. This group also reached a greater number of strokes (p = 0.049, d = 2.29) and strokes per minute (p = 0.046, d = 1.15). PAP with maximal conditioning contractions in rowing warm-up enhanced subsequent rowing sprint and is an advisable strategy to potentiate performance at the start of rowing competitions and sprint regattas.

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